Viral hepatitis resulting from a virus other than hepatitis A virus (HAV) and hepatitis B virus (HBV) has been referred to as non-A, non-B hepatitis (NANBH). More recently, it has become clear that NANBH encompasses at least two, and perhaps more, quite distinct viruses. One of these, known as enterically transmitted NANBH or ET-NANBH, is contracted predominantly in poor-sanitation areas where food and drinking water have been contaminated by fecal matter. The molecular cloning of a portion of this virus, referred to as the hepatitis E virus (HEV), has recently been described (Reyes et al.).
The second NANB virus type, known as parenterally transmitted NANBH, or PT-NANBH, is transmitted by parenteral routes, typically by exposure to blood or blood products. Approximately 10% of transfusions cause PT-NANBH infection, and about half of these go on to a chronic disease state (Dienstag).
Human sera documented as having produced post-transfusion NANBH in human recipients has been used successfully to produce PT-NANBH infection in chimpanzees (Bradley). RNA isolated from infected chimpanzee sera has been used to construct cDNA libraries in an expression vector for immunoscreening with chronic-state human PT-NANBH serum. This procedure identified a PT-NANBH specific cDNA clone and the viral sequence was then used as a probe to identify fragments making up 7,300 contiguous basepairs of a PT-NANBH viral agent (EPO patent application 88310922.5, filed Nov. 18, 1988). The same procedure was used by the present inventors to derive two of the PT-NANBH peptide and polynucleotide sequences disclosed herein. The sequenced viral agent has been named HCV (HCV) (above EPO patent application).
Heretofore, one immunogenic peptide encoded by the HCV viral agent has been reported (Choo, Kuo, EPO application 88310922.5). This peptide, designated C-100, has been used in immunoassays of PT-NANBH sera and found to react immunospecifically with up to 80% of chronic NANBH samples, and about 15% of acute NANBH samples (Kuo).
It is desirable to provide one or a collection of peptide antigens which are immunoreactive with a greater percentage of PT-NANBH-infected blood, including both acute and chronic PT-NANBH infection.